Stabilization of Lithium Metal Interfaces by Constructing Composite Artificial Solid Electrolyte Interface with...

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Rechargeable lithium metal batteries (LMBs) promise high energy density but face challenges with unstable interfaces, dendrite growth, and volume expansion, limiting safety and lifespan.
• Existing solutions often struggle to effectively manage the complex interfacial chemistry and mechanical stresses within LMBs.

Purpose of the Study:

• To engineer a stable and functional double-layer interface for lithium metal batteries.
• To investigate the mechanism of lithium deposition and solid electrolyte interphase (SEI) formation using a combined experimental and simulation approach.

Main Methods:

• A drop-casting method was employed to create a double-layer interface using mesoporous TiO2 and F-rich PFDMA.
• Experimental characterization and computational simulations were used to analyze the interface structure, Li+ binding, and SEI formation.
• Symmetric Li||Li cells and LiFePO4||Li cells were assembled to evaluate electrochemical performance.

Main Results:

• The TiO2 layer provided mechanical support and enhanced ionic conductivity, while PFDMA ensured sufficient F for LiF formation and improved electrolyte compatibility.
• The LiF-rich SEI formed due to preferential Li+-F binding, effectively inhibiting lithium dendrite growth and electrolyte decomposition.
• Symmetric Li||Li cells demonstrated over 800 hours of stable cycling, and LiFePO4||Li cells achieved 300 cycles at 1 C with a reversible capacity of 136.7 mAh g-1.

Conclusions:

• The developed double-layer interface significantly enhances the safety and cycle life of lithium metal batteries.
• This strategy offers a promising pathway for realizing next-generation high-energy-density storage devices.